The present invention concerns a weir for a solid-jacket centrifuge drum. The weir includes at least one channel for releasing a liquid phase that has been separated out inside the drum. A choke plate travels back and forth axially and is associated with the weir.
A weir of this type is known for example from Japanese 57-194 061 A2. The weir is intended to regulate the flow of solids out of the drum to maintain a particular concentration thereof. The weir rotates along with the drum and is connected at a bearing site to a stationary component that can be axially displaced. The bearing site must be sealed off from the escaping liquid phase. Designs of this type are complex and likely to malfunction.
Another weir is known from German 4 132 029 A1. It has a spinning chamber that varies the diameter of the weir between two different values. This approach makes it possible to adjust the level of liquid at start-up to prevent the liquid from surging over to the solids side.
It is, however, frequently desirable to continuously vary the level of liquid in the drum in order to optimize clarification and separation. German 3 921 327 A1 proposes various ways of doing so by varying the diameter of the aperture at the weir. The necessary components require transmission of the adjusting forces to rotating components, and the requisite transmission components can be sensitive to malfunction.